Population pharmacokinetics of intravenous and oral ciprofloxacin in children to optimize dosing regimens.

PURPOSE: This study aimed to characterize pharmacokinetics of intravenous and oral ciprofloxacin in children to optimize dosing scheme. METHODS: Children treated with ciprofloxacin were included. Pharmacokinetics were described using non-linear mixed-effect modelling and validated with an external dataset. Monte Carlo simulations investigated dosing regimens to achieve a target AUC0-24 h/MIC ratio ≥ 125. RESULTS: A total of 189 children (492 concentrations) were included. A two-compartment model with first-order absorption and elimination best described the data. An allometric model was used to describe bodyweight (BW) influence, and effects of estimated glomerular filtration rate (eGFR) and age were significant on ciprofloxacin clearance. CONCLUSION: The recommended IV dose of 10 mg/kg q8h, not exceeding 400 mg q8h, would achieve AUC0-24 h to successfully treat bacteria with MICs ≤ 0.25 (e.g. Salmonella, Escherichia coli, Proteus, Haemophilus, Enterobacter, and Klebsiella). A dose increase to 600 mg q8h in children > 40 kg and to 15 mg/kg q8h (max 400 mg q8h, max 600 mg q8h if augmented renal clearance, i.e., eGFR > 200 mL/min/1.73 m2) in children < 40 kg would be needed for the strains with highest MIC (16% of Pseudomonas aeruginosa and 47% of Staphylococcus aureus). The oral recommended dose of 20 mg/kg q12h (not exceeding 750 mg) would cover bacteria with MICs ≤ 0.125 but may be insufficient for bacteria with higher MIC and a dose increase according bodyweight and eGFR would be needed. These doses should be prospectively confirmed, and a therapeutic drug monitoring could be used to refine them individually.

Population Pharmacokinetics of Intravenous Ganciclovir and Oral Valganciclovir in a Pediatric Population To Optimize Dosing Regimens.

Ganciclovir is indicated for curative or preventive treatment of cytomegalovirus (CMV) infections. This study aimed to characterize ganciclovir pharmacokinetics, following intravenous ganciclovir and oral valganciclovir administration, to optimize dosing schemes. All children aged <18 years receiving ganciclovir or valganciclovir were included in this study. Pharmacokinetics were described using nonlinear mixed-effect modeling. Monte Carlo simulations were used to optimize the dosing regimen to maintain the area under the concentration-time curve (AUC) in the preventive or therapeutic target. Among the 105 children (374 concentration-time observations) included, 78 received intravenous (i.v.) ganciclovir, 19 received oral valganciclovir, and 6 received both drugs. A two-compartment model with first-order absorption for valganciclovir and first-order elimination best described the data. An allometric model was used to describe the bodyweight (BW) effect. Estimated glomerular filtration rate (eGFR) and medical status of critically ill children were significantly associated with ganciclovir elimination. Recommended doses were adapted for prophylactic treatment. To obtain a therapeutic exposure, doses should be increased to 40 mg/kg of body weight/day oral or 15 to 20 mg/kg/day i.v. in children with normal eGFR and to 56 mg/kg/day oral or 20 to 25 mg/kg/day i.v. in children with augmented eGFR. These doses should be prospectively confirmed, and therapeutic drug monitoring could be used to refine them individually. (This study has been registered at ClinicalTrials.gov under identifier NCT02539407.).

Population Pharmacokinetics of Intravenous and Oral Acyclovir and Oral Valacyclovir in Pediatric Population To Optimize Dosing Regimens.

Acyclovir is an antiviral currently used for the prevention and treatment of herpes simplex virus (HSV) and varicella-zoster virus (VZV) infections. This study aimed to characterize the pharmacokinetics (PK) of acyclovir and its oral prodrug valacyclovir to optimize dosing in children. Children receiving acyclovir or valacyclovir were included in this study. PK were described using nonlinear mixed-effect modeling. Dosing simulations were used to obtain trough concentrations above a 50% inhibitory concentration for HSV or VZV (0.56 mg/liter and 1.125 mg/liter, respectively) and maximal peak concentrations below 25 mg/liter. A total of 79 children (212 concentration-time observations) were included: 50 were taking intravenous (i.v.) acyclovir, 22 were taking oral acyclovir, and 7 were taking both i.v. and oral acyclovir, 57 for preventive and 22 for curative purposes. A one-compartment model with first-order elimination best described the data. An allometric model was used to describe body weight effect, and the estimated glomerular filtration rate (eGFR) was significantly associated with acyclovir elimination. To obtain target maximal and trough concentrations, the more suitable initial acyclovir i.v. dose was 10 mg/kg of body weight/6 h for children with normal renal function (eGFR ≤ 250 ml/min/1.73 m2) and 15 to 20 mg/kg/6 h for children with augmented renal clearance (ARC) (eGFR > 250 ml/min/1.73 m2). The 20-mg/kg/8 h dose for oral acyclovir and valacyclovir produced effective concentrations in more than 75% of children; however, a 15-mg/kg/6 h dose, if possible, is preferred. These doses should be prospectively confirmed, and therapeutic drug monitoring could be used to refine them individually. (This study has been registered at ClinicalTrials.gov under identifier NCT02539407.).

Development of a new patient-reported outcome measure to assess activities and participation in people with systemic sclerosis: the Cochin 17-item Scleroderma Functional scale.

BACKGROUND: Patient-reported outcome measures (PROMs) aimed at assessing people with systemic sclerosis (SSc) have rarely involved the target population in the item- and domain-generation stage of the instrument construction. OBJECTIVES: To develop a new PROM assessing activities and participation in people with SSc. METHODS: A provisional International Classification of Functioning, Disability and Health (ICF)-based 65-item questionnaire previously developed from interviews of people with SSc was sent by email to all patients followed in the internal medicine department of Cochin hospital (n = 184) and enrolled in the Scleroderma Patient-centered Intervention Network Cohort. Items were reduced according to their metric properties. Dimensional structure of the questionnaire was assessed by principal component analysis, convergent and divergent validities by Spearman's rank correlation coefficient, internal consistency by Cronbach's α, and reliability by a test-retest method using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. RESULTS: Overall, 113 of 184 patients (61·4%) completed the provisional questionnaire. The item-reduction process resulted in a 17-item questionnaire, the Cochin 17-item Scleroderma Functional scale (CSF-17). Principal component analysis extracted two dimensions: 10 items related to mobility (CSF-17 section A) and seven items related to general tasks (CSF-17 section B). We observed convergent validity of the CSF-17 total score with global activity limitation, pain, depression and aesthetic burden, and divergent validity with anxiety. Cronbach's α was 0·94 for section A and 0·95 for section B. ICC (n = 25 patients) was 0·92 for the CSF-17 total score. Bland-Altman analysis did not reveal a systematic trend for the test-retest. CONCLUSIONS: The CSF-17 is a new PROM assessing activities and participation specifically in people with SSc. Its content and construct validities are very high. What is already known about this topic? In the earliest stages of construction patient-reported outcomes (PROMs) for people with systemic sclerosis (SSc) rarely involve the target population. Instruments able to capture the specific needs of people with SSc in terms of activities and participation are lacking. What does this study add? The Cochin 17-item Scleroderma Functional Scale (CSF-17) is a new PROM assessing global activities and participation specifically in people with SSc. Patients' perspectives were prioritized at all stages of construction. What are the clinical implications of this work? The CSF-17 could be used in clinical practice and research to assess the efficacy of complex multidisciplinary interventions targeting activity limitations and participation restriction in people with SSc. Linked Comment: Clark and Denton. Br J Dermatol 2020; 183:610.

[Limits of parathyroid scintigraphy before surgery for hyperparathyroidism of renal origin]. / Limites de la scintigraphie parathyroïdienne avant chirurgie pour hyperparathyroïdisme d'origine rénale (51 cas).

AIM OF THE STUDY: To evaluate the results of parathyroid scinti scans (sestamibi or tetrofosmin) for detection of hyperplastic parathyroid glands responsible for renal hyperparathyroidism. METHODS: Injection of 15 mCi sestamibi or tetrofosmin and gammacamera acquisition of images focused on neck and mediastinum, 20 minutes and 2 hours thereafter. Injection of 150 mCi Iodine 123, acquisition of images 2 hours afterwards and visual subtraction. PATIENTS: 51 patients with renal insufficency or renal transplant were referred for surgical treatment of hyperparathyroidism. 52 scintiscans (sestamibi n = 19, tetrofosmin n = 33) were performed before operation (subtotal parathyroidectomy, bilateral thymectomy and parathyroid tissue cryopreservation). RESULTS: 180 hyperplastic parathyroid glands were resected, 71 of which had been detected by scintiscan. The factors modifying the results were the weight of the resected lesion and reoperation. All hyperplastic glands were detected in only 1 out of 41 scintiscans performed before first hand operations, whereas all missed glands were imaged in 8 out of the 10 explorations performed before reoperation for persistent renal hyperparathyroidism. The radionuclide, the type of hyperparathyroidism, the parathyroid location, patient's age and gender did not influence the results. No false-positive result was observed. CONCLUSION: Parathyroid scintiscan should not be routinely performed before the first neck exploration for renal hyperparathyroidism. It is mandatory in those cases needing reoperation for recurrent disease.